zsh: a proper powerline implementation, readable and extensible

zsh/init.zsh

@@ -9,14 +9,9 @@ confdir=$(dirname $0)
 conflist=(
     settings.zsh
     functions.zsh
+    prompt-powerline-native.zsh
 )
 
-if [[ -x $(whence powerline-go) ]]; then
-    conflist+=(prompt-powerline-go.zsh)
-else
-    conflist+=(prompt-plain.zsh)
-fi
-
 for config in $conflist; do
     [[ -r $confdir/$config ]] && . $confdir/$config
 done

zsh/prompt-powerline-native.zsh

@@ -1,67 +1,135 @@
-# Abandon all hope
-#
-# This is an implementation of powerline with git support.
-# The main feature is it being asynchronous: git status is updated in parallel.
-# Despite all the hours spent I have on this I am not going to use this atrocity.
-# But it's sorta funny to keep this around.
-#
-# I see now why common powerline prompts are usually not implemented in shell.
-
 prompt_fmtn='[ %%{\e[2;3m%%}%s%%{\e[0m%%} ] '
 printf -v PROMPT2 $prompt_fmtn '%_'
 printf -v PROMPT3 $prompt_fmtn '?#'
 printf -v PROMPT4 $prompt_fmtn '+%N:%i'
 prompt_state_file=/tmp/zsh_gitstatus_$$.tmp
 
-precmd.home() {
+PROMPT=
-    [[ $PWD =~ ^$HOME ]] && printf '~'
+typeset -A prompt_symbols=(
+    sep_a         $'\ue0b0'
+    sep_b         $'\ue0b1'
+    ellipsis      $'\u2026'
+    ro            $'\u2717'
+    ssh           $'\u2191'
+    git           $'\ue0a0'
+    git_unstaged  '±'
+    git_staged    $'\u2713'
+    git_untracked '!'
+    git_unmerged  '*'
+    bang          $'\n\U01f525'
+)
+typeset -A prompt_colors=(
+    fg             253
+    user           53
+    ssh            90
+    root           52
+    host           240
+    home           237
+    /              237
+    dirs           234
+    ro             124
+    git_branch     237
+    git_unstaged   130
+    git_staged     25
+    git_untracked  88
+    git_unmerged   30
+)
+
+precmd.prompt.clear() {
+    PROMPT=
 }
 
-precmd.cwd() {
+precmd.prompt.add() {
-    typeset shifted symbol=$' \ue0b1 ' cwd=${PWD#$HOME}
+    typeset string
-    [[ -z $cwd ]] && return
+    typeset data=$1 color=$2
-    typeset -a cwd_array=(${(ps:/:)cwd})
+    if [[ $color == same ]]; then
-    cwd=
+        PROMPT+="$prompt_symbols[sep_b] $data "
-    while ((${#cwd_array} > 3)); do
+    else
-        shift cwd_array
+        if ((${#PROMPT})); then
-        typeset shifted=1
+            PROMPT+="%F{$prev_color}%K{$color}$prompt_symbols[sep_a]%F{$prompt_colors[fg]} $data "
-    done
+        else
-    ((shifted)) && cwd_array=(... $cwd_array)
+            PROMPT="%K{$color}%F{$prompt_colors[fg]} $data "
-    while ((${#cwd_array})); do
+        fi
-        cwd+="$cwd_array[1]$symbol"
-        shift cwd_array
-    done
-    printf ${cwd%$symbol}
-}
-
-precmd.vars() {
-    typeset user_color=blue
-    ((UID)) || user_color=red
-
-    typeset -ga prompt_strings=(
-        %n::$user_color
-        %m::246
-        "$(precmd.home)::242"
-        "$(precmd.cwd)::245"
-    )
-}
-
-precmd.prompt() {
-    typeset prev_color symbol=$'\ue0b0' last=$'\n\U01f525 ' fg_color=black n=1 limit=${#prompt_strings}
-    typeset ps1 line val color
-    ps1=
-    for ((i=1; i<=limit; i++)); do
-        line=$prompt_strings[$i]
-        val=${line%%::*}
-        color=${line##*::}
-        if [[ -n $val ]]; then
-            [[ -z $prev_color ]] && prev_color=$color
-            ps1+="%F{$prev_color}%K{$color}$symbol%F{$fg_color} $val "
         prev_color=$color
     fi
+}
+
+precmd.prompt.bang() {
+    PROMPT+="%F{$prev_color}%k$prompt_symbols[sep_a]%f$prompt_symbols[bang] "
+}
+
+precmd.prompt.user() {
+    typeset user_color
+    ((UID)) && user_color=$prompt_colors[user] || user_color=$prompt_colors[root]
+
+    precmd.prompt.add %n $user_color
+}
+
+precmd.prompt.ssh() {
+    [[ -n $SSH_CONNECTION ]] && precmd.prompt.add $prompt_symbols[ssh] $prompt_colors[ssh]
+}
+
+precmd.prompt.host() {
+    precmd.prompt.add %m $prompt_colors[host]
+}
+
+precmd.prompt.cwd() {
+    typeset cwd limit=${1:-3}
+    if [[ $PWD =~ ^$HOME ]]; then
+        precmd.prompt.add \~ $prompt_colors[home]
+        cwd=${PWD#$HOME}
+    else
+        precmd.prompt.add / $prompt_colors[/]
+        cwd=${PWD:1}
+    fi
+    [[ -z $cwd ]] && return
+
+    typeset -a cwd_array=(${(ps:/:)cwd})
+    if ((${#cwd_array} > limit)); then
+        precmd.prompt.add $prompt_symbols[ellipsis] $prompt_colors[dirs]
+        while ((${#cwd_array} > limit)); do
+            shift cwd_array
+        done
+    else
+        precmd.prompt.add $cwd_array[1] $prompt_colors[dirs]
+        shift cwd_array
+    fi
+    while ((${#cwd_array})); do
+        precmd.prompt.add $cwd_array[1] same
+        shift cwd_array
+    done
+}
+
+precmd.prompt.ro() {
+    [[ -w . ]] || precmd.prompt.add $prompt_symbols[ro] $prompt_colors[ro]
+}
+
+precmd.prompt.pre_git() {
+    precmd.prompt.add "$prompt_symbols[git] $prompt_symbols[ellipsis]" $prompt_colors[git_branch]
+}
+
+precmd.prompt.git() {
+    typeset raw_status
+    raw_status=$(flock -n $prompt_state_file git --no-optional-locks status --porcelain -bu 2>/dev/null) || return 0
+
+    typeset -A count
+    typeset branch_status git_status_string IFS=
+    while read line; do
+        if [[ $line[1,2] == '##' ]]; then
+            branch_status=${line[4,-1]%%...*}
+            [[ $line =~ behind ]] && branch_status+=?
+            [[ $line =~ ahead  ]] && branch_status+=!
+            precmd.prompt.add "$prompt_symbols[git] $branch_status" $prompt_colors[git_branch]
+        fi
+        [[ $line[1,2] == '??'     ]] && (( count[git_untracked]++ ))
+        [[ $line[1,2] =~ .[MD]    ]] && (( count[git_unstaged]++  ))
+        [[ $line[1,2] =~ [MDARC]. ]] && (( count[git_staged]++    ))
+        [[ $line[1,2] =~ [ADU]{2} ]] && (( count[git_unmerged]++  ))
+    done <<< $raw_status
+
+    for i in git_unstaged git_staged git_untracked git_unmerged; do
+        (( count[$i] )) && precmd.prompt.add "$count[$i]$prompt_symbols[$i]" $prompt_colors[$i]
     done
-    ps1+="%F{$prev_color}%k$symbol%f$last"
-    echo -n $ps1
 }
 
 precmd.is_git_repo() {
@@ -69,50 +137,33 @@ precmd.is_git_repo() {
     [[ ! -e $git_dir/nozsh ]]
 }
 
-precmd.git() {
+precmd.prompt() {
-    typeset raw_status
+    precmd.prompt.clear
-    raw_status=$(flock -n $prompt_state_file git --no-optional-locks status --porcelain -bu 2>/dev/null) || return 0
+    precmd.prompt.user
-
+    precmd.prompt.ssh
-    typeset symbol=$'\ue0a0' branch_status git_status_string IFS=
+    precmd.prompt.host
-    typeset staged_count unstaged_count untracked_count unmerged_coun
+    precmd.prompt.cwd 2
-    while read line; do
+    precmd.prompt.ro
-        if [[ $line[1,2] == '##' ]]; then
-            branch_status=${line[4,-1]%%...*}
-            [[ $line =~ behind    ]] && branch_status+=?
-            [[ $line =~ ahead     ]] && branch_status+=!
-            prompt_strings+=("$symbol $branch_status::249")
-        fi
-        [[ $line[1,2] == '??'     ]] && (( untracked_count++ ))
-        [[ $line[1,2] =~ .[MD]    ]] && (( unstaged_count++  ))
-        [[ $line[1,2] =~ [MDARC]. ]] && (( staged_count++    ))
-        [[ $line[1,2] =~ [ADU]{2} ]] && (( unmerged_count++  ))
-    done <<< $raw_status
-    if ! ((untracked_count || unstaged_count || staged_count || unmerged_count)); then
-        prompt_strings+=(ok::10)
-    fi
-
-    (( unstaged_count  )) && prompt_strings+=( "~$unstaged_count::11" )
-    (( staged_count    )) && prompt_strings+=( "+$staged_count::12"   )
-    (( untracked_count )) && prompt_strings+=( "-$untracked_count::9" )
-    (( unmerged_count  )) && prompt_strings+=( "*$unmerged_count::14" )
 }
 
 precmd.git_update() {
-    precmd.vars
+    umask 077
-    precmd.git
+    precmd.prompt
-    precmd.prompt > $prompt_state_file
+    precmd.prompt.git
+    precmd.prompt.bang
+    > $prompt_state_file <<< $PROMPT
     kill -s USR1 $$
 }
 
 precmd() {
     if precmd.is_git_repo; then
-        precmd.vars
+        precmd.prompt
-        prompt_strings+=($'\ue0a0 ...'::249)
+        precmd.prompt.pre_git
-        PROMPT=$(precmd.prompt)
+        precmd.prompt.bang
         precmd.git_update &!
     else
-        precmd.vars
+        precmd.prompt
-        PROMPT=$(precmd.prompt)
+        precmd.prompt.bang
     fi
 }